N: Auditory and Vestiubular

Question 1

The ______ division of CN VIII is responsible for hearing and the _______ division is responsible for head position and movement.

Answer 1

cochlear; vestibular

Question 2

The vestibulocochlear structures are found in the ________ part of the temporal bone.

Answer 2

petrous

Question 3

Within the bony labyrinth there is a _______ tube suspended in a _____ tube.

Answer 3

Membranous; bony

Question 4

The perilymphatic space is filled with ________ and is continuous with the _________ space.

Answer 4

perilymph; subarachnoid

Question 5

T/F: Perilymph fills the membranous labyrinth.

Answer 5

FALSE

Endolymph

Question 6

What cells secrete endolymph?

Answer 6

Stria vascularis

Question 7

Where are hair cells found?

Answer 7

Within membranous labyrinth

Question 8

_______ project out of hair cells and into the endolymph.

Answer 8

Stereocilia

Question 9

The tallest stereocilia is called the _______.

Answer 9

kinocilium

Question 10

T/F: The kinocilium are only found in the vestibular portions.

Answer 10

TRUE

Question 11

Where do the tallest stereocilia project?

Answer 11

Gelatinous mass

Question 12

What starts a signal in the hair cells?

Answer 12

Stereocilia deflect toward tallest -> stretches tip links -> depolarizes hair cell

Question 13

What determines the type of signal that is sent from the hair cell.

Answer 13

The arrangement of stereocilia

Question 14

What is the auditory receptor organ?

Answer 14

Organ of corti

Question 15

T/F: The inner ear is fluid filled.

Answer 15

TRUE

Question 16

T/F: The membrane is suspended in perilymph and filled with endolymph.

Answer 16

TRUE

Question 17

Which part of the inner ear is shaped like a snail shell?

Answer 17

Cochlea

Question 18

What determines sound intensity?

Answer 18

Rate and number of fired nerves

Question 19

What determines sound frequency?

Answer 19

Location of cells stimulated in organ of corti

Question 20

T/F: The location of sound is determined in the CNS using stimuli from both ears.

Answer 20

TRUE

Question 21

T/F: The apex of the basilar membrane responds to high frequencies.

Answer 21

FALSE

Floppy Apex =Low
Stiff Base = high

Question 22

Where are the cell bodies for the nerves stimulated by hair cells?

Answer 22

Spiral ganglion

Question 23

The nerves stimulated by hair cells synapse at the ______ and ______ cochlear nuclei?

Answer 23

Dorsal and ventral

Question 24

Where do second order fibers from the dorsal cochlear nucleus go?

Answer 24

Lateral lemniscus

Question 25

T/F: Fibers from the ventral cochlear nucleus are involved with sound localization.

Answer 25

TRUE

Question 26

What is the path of a signal from hair cells after entering the lateral lemniscus?

Answer 26

Lateral lemniscus -> inferior colliculus -> MGN (thalamus) -> transverse temporal gyri

Question 27

What are the three main functions of the vestibular system?

Answer 27

1. Regulate posture 2. Coordinate eye movement 3. Coordinate head movement

Question 28

What makes up the bony parts of the vestibular division?

Answer 28

Vestibule and three semicircular canals

Question 29

What makes up the membranous portion of the vestibular division?

Answer 29

1. Saccule 2. Utricle 3. three semicircular ducts

Question 30

What structures are found in the ampula of each semicircular duct?

Answer 30

1. Crista: supporting and hair cells | 2. Capula: angular acceleration

Question 31

What type of rotation is not able to be felt by the semicircular ducts?

Answer 31

Continuous rotation

Question 32

The utricle and saccule each have a tuft of hair cells called the _____.

Answer 32

Macula

Question 33

What is the name of the gelatinous mass in the vestibular system?

Answer 33

Otolithic membrane

Question 34

The _____ responds to side/side motion. The _____ responds to up/down motion.

Answer 34

Utricle; Saccule

Question 35

Describe the path of a signal in the vestibular system.

Answer 35

Hair cells -> CN VIII processes -> vestibular ganglion -> jextarestiform body -> cerebellum

Question 36

What are the four vestibular nuclei in the vestibular nuclear complex?

Answer 36

1. Inferior 2. Medial 3. Lateral 4. Superior

Question 37

Where do efferents from the vestibular nuclei go and what is their functions?

Answer 37

1. Spinal cord: posture 2. Cerebellum: head movement 3. CN III, IV, VI: eye movement 4. Visceral nuclei: autonomic effects 5. Thalamus -> cerebrum: conscious awareness

Question 38

T/F: The lateral vestibulospinal tract is for posture and the medial tract is for head stabilization.

Answer 38

TRUE

Question 39

Which efferent fibers generate eye movements to compensate for head movements?

Answer 39

Projections to CN III, IV, and VI

Question 40

What part of the ear does alcohol affect?

Answer 40

Cupula in the inner ear

Question 41

What are the three systems that work so you know your position?

Answer 41

1. Vestibular 2. Proprioception 3. Visual

Question 42

T/F: You only need one of the three position sense systems to function normally.

Answer 42

FALSE Need two!

Question 43

What are the three possible hair cell locations in the ear?

Answer 43

1. Organ of corti (cochlea) 2. Cristae (semicircular duct) 3. Maculae (utricle, saccule)

Question 44

What are the three gelatinous materials and where are they?

Answer 44

1. Tectorial membrane (organ of corti) 2. Cupula (cristae) 3. Otolithic membrane (maculae)

Question 45

T/F: The cupula transmits stimulus for sound.

Answer 45

FALSE Tectorial membrane = sound Cupula = angular acceleration